1. Field of Invention
The present invention relates to a nonvolatile semiconductor memory and a method for controlling the same.
2. Description of Related Art
The related art includes various types of nonvolatile semiconductor memories. One such related art memory is a MONOS (metal-oxide-nitride-oxide-semiconductor/-substrate) nonvolatile semiconductor memory (see U.S. Pat. No. 6,044,022 and U.S. Pat. No. 6,081,456). This type of memory has an electron trap region between the gate electrode and substrate of its memory element. The amount of electrons in the trap region is controlled by electric-field control. The electrons in the trap region being stored for a long period of time, this type of memory works as a nonvolatile memory.
This type of memory, however, possibly involves write errors and erase errors to and from non-selected memory elements under the influence of disturbing voltage. In order to address this problem, the related art sacrifices the packaging density and access speed of memory elements in related art.